South Korea on Friday brushed off the North’s offer of reconciliation through the cessation of slander and military drills with the US, calling for action toward denuclearisation to prove its sincerity.

Pyongyang’s powerful National Defense Commission made the “crucial proposals” late Thursday, which also included taking a “mutual practical measure to prevent a nuclear holocaust.” Such steps would help resolve inter-Korean issues such as reunions of separated families, it said.

The Key Resolve and Foal Eagle exercises slated to begin next month with the US are annual, defensive programmes and in line with international norms, it said.

“North Korea called for an end to slander only two years ago through the New Year address but has since continued slander and threats against us,” ministry spokesman Kim Eui-do said in a statement.

“North Korea should bear in mind that it must earn trust not by words, but by action.”

The North’s offer marked a follow-up to this year’s New Year speech by leader Kim Jong-un, who called for efforts to enhance cross-border relations and achieve reunification.

But the ministry's four-point statement stroke a harsh tone, apparently reflecting President Park Geun-hye’s disappointment at Pyongyang’s rejection of her offer of talks to arrange the first family reunion in more than three years for the upcoming Lunar New Year holidays in her own New Year address last week.

While lambasting the North’s nuclear programme, the ministry demanded “responsible measures” to address the regime’s past provocations such as the 2010 attacks on a South Korean corvette and border island.

“The essence of the nuclear issue originates from North Korea’s nuclear development,” it said, calling for “substantial action toward denuclearisation.”

“The separated family issue is an urgent, purely humanitarian one that cannot be linked with political and military situations.”